Lightroom is a very capable printing engine, it also makes printing very simple. You can get to the print module, by clicking on the Print tab on the right hand side of Lightroom. When you open the Print module and you have a picture selected in the film strip, you will see an image in the centre of the application with a white background. This view is a visual representation of the paper and how the image will look on the page once printed.
The page setup button (marked Red) allows configuration of the paper size that will be used in the printer. There are pre-configured paper sizes in the paper size drop down list (marked Yellow). There is also an option to create custom sizes in this list as well (marked Pink).
For example if you would like to print an image and you have a 24inch Large Format printer that is roll fed.
Normally you would print the image with the width as 24 inch, but you may want to print the 24 inch on the small edge and then run the long edge vertically (to make use of the roll). This will enable you to print large prints from Lightroom.
The image below is 23inches wide with 16 inches high, but we may want to print this at 24inch on the short side and then recalculate the long edge, so let us see how you this is created and managed inside Lightroom.
This arrangement can be configured easily in Lightroom in the page setup button (marked Red below).
Clicking the Page setup button will open up the page dialog. The page size can be changed for standard sizes like A4, A3 etc. We can also specify custom sizes in this list. The custom sizes dialog opens up the dialog box on the right (marked Pink). We are able to specify the new length in mm in the top of the pink box.
Let us look at another print, this one is a panoramic and will be more complicated.
What if we want to print this image at 24 inches on the short edge and the long size along the length of the roll, but we don’t know the length, as it’s custom.
The aspect ratio of this image is 14337px x 6228px. So If we would like to print the long edge to 24 inches, then 6228px will be set to 24 inches. To calculate the length we need to divide the long edge by the short edge and multiply by 606.9mm (606.9mm is 24inches), this will give us the total length of the long edge
The working out
The actual size of the long edge is 14337px / 6228px = (2.3 * 606.9) = 1396mm, rounded up to 1400mm.
Here is the new custom size.
This equates to Lightroom as at 24inch x 55inch print, you may just need to change the paper rotation and the image rotation to make it show correctly. You can see that the final print is the represented in Lightroom and will be printed as so (before you print don’t forget to check the ICC profile)
There you have a safe way to print huge images using rolls of paper.